SEPTEMBER 2012 - The most powerful digital camera in the world takes the first images and starts the study of dark energy

With the participation of the Institute for High Energy Physics (IFAE) and the Institute for Spatial Sciences (ICE) the most powerful digital camera in the world takes the first images and starts the study of dark energy.

• Dark Energy Camera (DECam) of the Dark Energy Survey (DES) collaboration achieved its first light images last Wednesday, September 12, 2012, and it will start making a detailed map of an octant of the sky before the end of this year.

• Two catalan institutions, the Institute for Spatial Sciences (ICE, IEEC/CSIC) and the Institute for High Energy Physics (IFAE), together with the CIEMAT and the Universidad Autónoma de Madrid (UAM), participate in this international collaboration lead by Fermilab, in USA.

Bellaterra, September 17, 2012.

Eight billion years ago, rays of light from distant galaxies began their long journey to Earth. That ancient starlight has now found its way to a mountaintop in Chile, where the newlyconstructed Dark Energy Camera, the most powerful sky-mapping machine ever created, has captured and recorded it for the first time.

That light may hold within it the answer to one of the biggest mysteries in physics – why the expansion of the universe is speeding up. Scientists in the international Dark Energy Survey collaboration announced this week that the Dark Energy Camera, the product of eight years of planning and construction by scientists, engineers, and technicians on three continents, has achieved first light. The first pictures of the southern sky were taken by the 570-megapixel camera on Sept. 12.

The construction of this camera is the result of an international collaboration, with the direct involvement of the ICE (CSIC/IEEC) and the IFAE in Barcelona and the CIEMAT, in collaboration with the UAM, in Madrid. The Spanish consortium has played a key role in the construction and operation of DECam, designing, building and verifying high speed electronics that reads and controls the camera CCDs, and also in designing and implementing the software that, on one hand, allows the telescope to be directed with precision and, on the other, produces large-scale simulations of the universe that develop and test methods of scientific analysis. International DES collaboration is formed also by scientists from the U.S., UK, Brazil, Germany and Switzerland, and is led by the Fermi National Accelerator Laboratory (Fermilab), USA.

That camera has been mounted on the Victor M. Blanco telescope at the National Science Foundation’s Cerro Tololo Inter-American Observatory (CTIO) in Chile, which is the southern branch of the U.S. National Optical Astronomy Observatory (NOAO). With this device, about 11 tons that move and focus with a precision of micrometers, astronomers and physicists will probe the mystery of dark energy, the force they believe is causing the universe to expand faster and faster.

ICREA Research Professor Ramon Miquel explains that the goal of DECam is Help us understand why the universe's expansion is accelerating, which is probably now the most profound mystery in all of science. We are very pleased to see how, after the efforts of many people over the past eight years, we're finally ready to start this adventure.

The Dark Energy Camera is the most powerful survey instrument of its kind, able to see light from over 100,000 galaxies up to 8 billion light years away in each snapshot. The camera’s array of 62 charged-coupled devices has an unprecedented sensitivity to very red light, and along with the Blanco telescope’s large light-gathering mirror (which spans 13 feet across), will allow scientists from around the world to pursue investigations ranging from studies of asteroids in our own Solar System to the understanding of the origins and the fate of the universe.

Scientists in the Dark Energy Survey collaboration will use the new camera to carry out the largest galaxy survey ever undertaken, and will use that data to carry out four probes of dark energy, studying galaxy clusters, supernovae, the large-scale clumping of galaxies and weak gravitational lensing. This will be the first time all four methods will be possible in a single experiment.

CSIC Research Professor Enrique Gaztañaga highlights These large maps also draw cosmic history, as a real time machine. We compare the rate and expansion history of the universe with the growth rate of its structures. This will allow us to confirm or refute the model we have about the origin of the cosmos and its fundamental laws. The participation of our institutions in this mapping allows us to be at the forefront of research and instrumentation, on the border of the unknown.

The Dark Energy Survey is expected to begin in December, after the camera is fully tested, and will take advantage of the excellent atmospheric conditions in the Chilean Andes to deliver pictures with the sharpest resolution seen in such a wide-field astronomy survey.

Over five years, the survey will create detailed color images of one-eighth of the sky, or 5,000 square degrees, to discover and measure 300 million galaxies, 100,000 galaxy clusters and 4,000 supernovae.